Aircraft-engine control



Dec. 6, 1927.

s. HEATH.

' AIRCRAFT ENGINE common Original Filed Now. 21, 1923 Patented Dec. 6, 1927.

PATENT OF FlCE.

SPENCER HEATH, 0F ELKRIDGE, MARYLAND.

AIRCRAFT-ENGINE CONTROL.

Application filed November 21, 1928, SeriaI'IIo. 676,190. .Renewed May 16, 1927.v

This invention relates to engine control and has special reference to aircraft engines in connection with variable or reversible pitch propellers or with other mechanism in accordance with the operation of which it is desired tocontrol the power and speed of the engine by regulating the admission of fuel or by other means of engine control.

One object of this invention is to provide engine control means directly responsive to changes takin place in other mechanism such as'a varia 1e pitch propeller, gear shift,

. objects to appear as or, reversing gear mechanism or mechamsm responsive to variations in the speed of travel.

A further object is to provide engine control means directly responsive to changes taking place in other mechanism and also responsive to manual means ofv control without necessity of disengaging either control means in order to allow free operation of the other. A .further object is to provide combined automatic or mechanical and .manual control means. V

A further object is to provide combined automatic and manual .control means in which the manual control serves to fix the engine speed or the speed of travel and theautomatic control serves to hold the engine or the vehicle at or near the speed so fixed. With these objects in view and further my invention is fully disclosed I have invented the engine control shown by the annexed-drawings which illustrate one of the forms in which my invention may be embodied and in" which:

Figure 1 is a side view of my invention as em loyed to insure safety of engine speed; ig. 2 is a side view. as applied to obtaining uniform speed of travel through engine control.

Fig. 3 is a plan view of Fig. 2.

Fig. 4 is a diagrammatic side view as ap-.

plied to the combined functions of Fig. 1

and Fig. 2.

Referring to the drawings, 1 is the carburetor containing a throttle valve opened and closed by arm 7 mounted on shaft 8 is Variable in position in accordance with any-change of pitch in the propeller blades or'any engaging or disengaging of transmission, orreverse gears.

21 (Fig. 1) is a shaft connected with the movement'of the arm2. Theoperating mechanism of a reversible propeller (or with a reversing gearing). This shaftcarries a cam 20 which moves the arm when the propeller is at zero pitch (or the reverse gearing is in neutral position) and nearest to the cam center when the propeller is in full pitcheither forward or reverse (or when the gearing is in mesh).

Movements of arm 7 are communicated to the throttle valve arm 2 through rod 9, lever 10 and rod 11 as shown, the mid portion'of lever 10 being fulcrumed at 18 on the end of rodd12. The rod 12, passing through the gu1 e 17, is connected-at 13 with the arm 3 mounted on shaft 4 which carries the sheave 5 formanual throttle control by the cables 6 which are connected with any customary form of throttle lever convenient to the pilots hand.

The dotted line 15 connecting the-throttle valve arm 2 with the end of the arm 3 shows the position of the customary linkage when manual control -.of the engine alone is employed. My combined manual and automaticcontrol is eifected by dispensing with the customary direct connection along; the

line 15 and connecting the throttle valve arm 2 with the arm 3 by means of rod 11, lever 10 and-the sliding rod 12 connected to arm,

3 at 13, which is nearer to the center than the point of con-nectionla of the, original connection along the line 15. By this means thethrottle arm 2 may be made to respond to manual control thmughrod' 12, when no movement is taking place in arm 7, in precisely the samemanner as though it were transmitted through a connection along the line 15, with this advantage, however, that when any movement takes place in arm .7, dueto a change of shifting of transmission gears or the this change, acting through the rod 9 moves lever 10 about its fulcrum 18 and thus, through rod '11, communicates a change to the throttle. valve arm 2.

propeller blade pitch, I

like,

As applied in connection with a variable rods 9 and 11 and lover 10, a sufficient movement of throttle arm 2 to partially close the throttle and thus either diminish or prevent any undesirable increase in the speed of the motor while the blades are at or near their zero pitch position. Oorrespondingly, when the propeller blades are moved in the direction of greater pitch, either forward or reverse pitch, the

arm 7 moves in the direction of the arrow these operations, however,

and thus opens the throttle sufiiciently to maintain a equate engine speed under the -g'rezifer load due to increase of propeller p1tc In a similar manner arm 7 may be governed as to movement and position by connection with a clutch or a gear shift mechanism so that when the engine is disengaged the arm will move in the direction of the arrow C and thus partly or entirely close the throttle valve durin disengagement, likewise moving in the direction of the arrow 0 and opening the throttle valve upon re-eng ement of the engine power. I

. igures 2 and 3 show my control mechanism as adapted for governing the speed of flight or aircraft. For this purpose the arm 7 and shaft 8 are connected with a device having movable parts responsive to changes of pressure and relative velocity of the air. I have represented this in the form of a pressure plate 27 carried on the forward end of a bar 28 slidabl mounted in fixed su ports 31 and 32. gpring 29 holds the pressure plate forward against pressure of the wind or to the limit set by the collar 30. The arm 26 mounted on shaft 8 has its upper end divided to pass on either side of bar 28 and slotted to receive pin 33 passing through this bar. By this device an increase of wind pressure moves the bar 28 backwards and acts throu h arm 26, shaft 8, arm 7 rod 9, lever 10, r0 11 and arm 2 to cut own the throttle opening and reduce the ower. Similarly a decrease of speed b re ucing the pressure on plate '27 acts in t e opposite manner to open wider the throttle valve and increase the engine power. Throughout the speed of flight is fixed or altered by the position or movement of rod 12 under manual control. If rod 12 is moved forward towardsv the left this increases the throttle opening and thus the pressure plate- 27 becomes operative to affect the throttle opening and control the speed at this higher range of'sp'eed and pres sure. In like manner a movement of rod 12 to the right reduces the throttle and fixes a lower level of speed but always under control of pressure plate 27.

While I have shown mv en ine control in Figs. 2 and 3 as connected'wit aspeed governing device. actuated. by a pressure plate, it is to be understood that this is illustrative, and that any other form of speed governor such as one acting on the principle of the Pitot tube or an electro-magnetic device might be employed within thescope of my invention.

In Fig. 4 I have shown by diagram how my invention may be applied to control the engine speed when reversing propeller pitch and at the same time to securing uniformity in the speed of flight. The amount of engine power is set by the manually operated rod 12 acting on lever 10 by moving its ful crum 18 and thus acting on the throttle lever 2 through the connection 11. The connection 9, jointed and slidable in guides 17, connects with a second lever 10 at its center portion 18. 19, 20, 21 and 37 rep-resent the mechanism operated in accordance with changes in propeller pitch as shown in Fig.

1, but acting on connection 9 indirectly through the member 10 instead of directly as in Fig. 1. 27, 28, 33, etc., represent a pressure plate with its mechanism responsive to the speed of flight as shown in. Fig.2. This also acts on connection 9 throu h the combining member 10 instead of directly as in Figure 2. Thus these two mechanisms exert their combined influence on lever 10 in the same manner as each of them separately in Fi ures 1 and 2.

- aving now fully described myinvention, what I claim is:

1. The combination with a variable pitch propeller an engine and power-control means therefor, of a movable element coacting with the adjustment of-said propeller, a lever, connections from said movable element to said lever and from said lever to said powercontrol means for engine control in accordance with propeller pitch, and means for adjustment of the fulcrum of said lever whereby said power-control means ma be set for full power or part power wit out afi'ecting the operation of said movable element as an en 'ne control.

2. The com ination with a-variable pitch propeller an engine and power-control means therefor, of a movable element coacting with the adjustment of said propeller, a sl1dably mounted member, a lever fulcrumed on said slidable member, connections from said movable element to said lever and from said lever to said power-control means for en ine con-- trol in accordance with propeller pitch, and means for adjustment of said slidable member whereb said power-control, means may be set for ullpower or part powerwithout affecting the operation of said movable 918-. ment as an en me control.

3. The com ination with a variable itch ropeller an engine and throttle valve t e'reconnections from Sflld movable arm to said lever and from said'lever to said throttle valve for engine control in accordance with propeller pitch, and means for adjustment of the fulcrum of said lever whereby said throttle valve may be set wide open or partly open without affecting the operation of said cam and movable arm as an engine control.

4. The combination with an engine and power-control means therefor, of mechanism having a variable element, a slidably mounted member, a lever fulcrumed on said slidable member, connections from said variable element to said lover and from said lever to said power-control means, and means for adjustment of said slidable member whereby said power control means may be set for full power or part power without affecting the operation of said variable element as an engine control. p y

5. The combination with an engine and throttle valve therefor, of mechanism having a variable element, a lever, connections from said variable element to said lever and from said lever to said throttle valve, and means for adjustment of the position of the fulcrum of said lever whereby said throttle valve may be set wide open or partly open without affecting the operation of said variable element as an engine control.

6. The combination with an engine and throttle valve therefor, of a plurality of variable mechanisms, a combining member adapted to be acted upon by the' several mechanisms. a lever, connections from said combining member to said lever and from said lever to said throttle valve, and means for adjustment of the fulcrum of said lever whereby said throttle valve may be set wide open or partly open without affecting the operation of the several mechanisms through said combining member to control the en- 1118. g In testimony whereof I hereunto aflix my signature.

SPENCER HEATH, 

